DENVER – Former House speaker John Boehner is dropping his long-held opposition to marijuana and joining the board of a rapidly expanding cannabis company.

Boehner, who left the House in 2015, briefly served on the board of tobacco giant Reynolds American after his retirement. He said in a statement Wednesday that his thinking on marijuana has "evolved," prompting him to join New York-based Acreage Holdings, along with former Massachusetts governor Bill Weld, also a Republican.

"I’m convinced de-scheduling the drug is needed so we can do research, help our veterans, and reverse the opioid epidemic ravaging our communities," Boehner tweeted.

For decades, the federal government has classified marijuana as a Schedule 1 substance, treated on par with heroin and cocaine. But 30 states and the District of Columbia already permit medical marijuana use of some kind, and nine states and the District of Columbia also permit recreational use by adults.

Legalization advocates say it's only a matter of time before Congress is forced to reschedule marijuana at the federal level. A federal change could replace the patchwork of state-level legalization laws, permit distribution of marijuana across state lines and allow marijuana firms to get bank accounts.

“We’re regulated somewhere between alcohol and nuclear waste," said Michael Ray, CEO of California-based marijuana company Bloom Farms. "In many ways, they don’t even regulate pharmaceuticals as much.”

More than 60% of Americans believe recreational marijuana should be legal, double its popularity in 2000, according to a January 2018 poll by the Pew Research Center. Popularity for medical marijuana is even stronger: 88% of Americans think medical cannabis should be legal, according to April 2017 CBS News poll.

Republican members of Congress are increasingly the recipients of marijuana lobbying dollars as the industry has grown more sophisticated and comfortable with its power.

While many cannabis activists welcomed Boehner's change of heart, some critics complained that he's yet another wealthy white man able to slide into the marijuana industry while tens of thousands of Americans — particularly young black men — remain jailed on drug charges.

Some cities and states have deliberately written their legalization rules to help convicted drug dealers get marijuana sales licenses, and prosecutors in California have even begun wiping out drug possession convictions for some low-level offenders.

Actor Jeffrey Wright tweeted a picture of a confused looking dog with the caption: "All the brahs in prison on weed charges hearing former Speaker of the U.S. House of Representatives John Boehner’s first public remarks on behalf of the marijuana industry..."

All the brahs in prison on weed charges hearing former Speaker of the U.S. House of Representatives John Boehner’s first public remarks on behalf of the marijuana industry... pic.twitter.com/JfwhsS39LM

Added longtime marijuana legalization advocate Dan Riffle: "Disappointing to see MJ movement folks doing a victory lap over the Boehner news, as if it's worth celebrating. If cannabis stores were mostly run by black felons, I'd celebrate. That this guy can go straight to the front of the line shows we're failing."

The National Organization for the Reform of Marijuana Law, or NORML, repeatedly rated Boehner as an "anti-legalization" politician.

Legalization opponents, who long have tried to tie the nation's marijuana industry to Big Tobacco, mocked Boehner's announcement. Kevin Sabet of Smart Approaches to Marijuana argues the U.S. should consider decriminalizing marijuana instead of creating a massive new industry selling an intoxicating substance.